Forehead pad for respiratory mask

ABSTRACT

A forehead pad for use in a respiratory mask with a forehead support, which includes a base portion to contact a user&#39;s forehead, a support post connected to the base portion, and a head adapted to connect the support post to a forehead support. A pair of forehead pads may be joined with a connector.

CROSS-REFERENCE TO PRIORITY APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication Ser. No. 60/424,696 filed Nov. 8, 2002 and U.S. ProvisionalApplication Ser. No. 60/467,572 filed May 5, 2003, and the presentapplication is a Continuation-In-Part of U.S. Non-ProvisionalApplication Ser. No. 10/235,846 filed Sep. 6, 2002, now U.S. Pat. No.6,823,869, which in turn claims priority to U.S. Provisional PatentApplication Ser. No. 60/317,486 filed Sep. 7, 2001 and U.S. ProvisionalPatent Application Ser. No. 60/342,854 filed Dec. 28, 2001. Each of theabove applications is hereby incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to forehead pads. These pads can be used with arespiratory mask for Non-invasive Positive Pressure Ventilation (NPPV)treatment of Sleep Disordered Breathing (SDB).

2. Background of the Invention

Nasal masks are commonly used in the treatment of respiratory conditionsand sleep disorders by delivering a flow of breathable gas to a user toeither assist the user in respiration or to provide a therapeutic formof gas to the user to prevent sleep disorders such as obstructive sleepapnea (OSA). These nasal masks typically receive a gas through a supplyline, which delivers the gas into a chamber formed by walls of the mask.

The mask is generally semi-rigid and has a face portion that is incommunication with the nose and/or mouth of a user. The mask is normallysecured to the user's head by straps. The straps are adjusted to pullthe mask against the face with sufficient force to achieve a gas-tightseal between the mask and the user's face. Gas is thus delivered to themask through the aperture to the user's nasal passages and/or mouth.

One of the problems that arises with the use of the mask is that inorder for the straps to be tight, the mask is compressed against theuser's face and may push unduly hard on the user's nose. Additionallythe mask may move around on the user's face. Therefore, masks oftencontain a forehead support that creates addition contact points betweenthe mask and the user's head. The forehead support minimizes themovement of the mask as well as minimizes uncomfortable pressure pointsof the mask by preventing the mask from pushing too strongly against theuser's nose and/or facial region.

Forehead supports typically have attached thereto a soft comfortablepatient-contacting forehead pad. Forehead pads are generally constructedfrom soft materials, such as silicone, in contrast to the foreheadsupport, which is generally rigid. One form of prior art forehead pad isdisclosed in U.S. Pat. No. 6,119,693, the contents of which are herebyincorporated by reference in their entirety.

A problem with existing forehead pads is the mechanism by which the padis connected to forehead support. The pad must be secured in such a wayso as to be easy to insert and remove, but not be unintentionallydislodged. Furthermore, regardless of the relative proximity between theforehead support/pad and the mask frame, there should be no sharp edgesagainst which the user's face can make contact, leading to furtherdiscomfort.

One form of known forehead pad is used on the AIR PILOT mask,manufactured by MPV, Truma, Germany, shown in FIGS. 50 to 57. Thisforehead pad includes a stalk adapted to be pulled through a hole on anarm of a forehead support. The pad also includes two rows of three slotsadapted to engage with two rows of three teeth which project rearwardlyfrom the arm of the forehead support. Problems with this type offorehead pad include: (i) it is difficult to assemble; (ii) it isdifficult to remove; (iii) it may become dislodged during the night andpresent sharp teeth to the forehead of a patient; (iv) it has a vagueassembly which makes it difficult to know when it is in the correctposition; (v) its construction leads to regions of high pressure underthe teeth; and (vi) it presents an edge to the forehead of a patientwhen rocked at an angle.

A further problem with existing forehead pads is that they can lead touneven pressure on the user's forehead, leading to discomfort and markson the face. For example, one form of known forehead pad includes apatient contacting surface and a pair of reinforcing struts, as shown inFIGS. 16 to 17. During use, the pad is subject to a compressing forcethat can lead to pressure points, lines or ridges on the patientcontacting surface in the region where the reinforcing struts join it.This can lead to uneven pressure on the user's forehead. The use ofexisting forehead pads also results in sweating by the user.

Another problem with a known form of forehead support is the mechanismfor engaging the forehead pad with the forehead support. The foreheadsupport includes a pair of rigid L-shaped catches c adapted to slidablyengage with a recess in the forehead pad, as shown in FIGS. 18 to 20. Aproblem can arise if a pad is not in position when the forehead supportis in use: the catch may abut against the forehead of a user. This canlead to discomfort and marking of the forehead.

Therefore, there exists a need in the art for a forehead pad thatovercomes the problems listed above.

SUMMARY OF THE INVENTION

One aspect of the invention is directed towards a mask assembly having aforehead support and a forehead pad that provide more comfort to a user.

Another aspect of the invention is directed towards a forehead pad thatdistributes contact pressure around the user's forehead.

Another aspect of the invention is directed towards a forehead pad thatpermits a wide range of motion.

Another aspect of the invention is directed towards a forehead pad thatlessens or avoids contact between the user and the edges of the foreheadpad.

Another aspect of the invention is directed towards a forehead pad thatachieves an even pressure distribution with no localized regions of highforces.

Another aspect of the invention is directed towards providing a foreheadpad that is easy to insert in a forehead support and is flexible enoughto accommodate a range of different forehead sizes and shapes.

Another aspect of the invention is directed towards a forehead pad thattapers smoothly from the support post to the base region, causing linesof force to be smoothly and evenly carried from the support post to thebase region, resulting in an even distribution of the pressure across auser's forehead.

Another aspect of the invention is directed towards a forehead pad for aforehead support of a respiratory mask that comprises a plate regionconnected to a support post, the support post including a foreheadsupport engaging mechanism.

Another aspect of the invention is directed towards a forehead pad thatit is relatively easy to engage with a forehead support but relativelymore difficult to disengage.

Another aspect of the invention is directed towards a forehead pad thatlessens or avoids contact between the user and the edges of the foreheadsupport.

Another aspect of the invention is directed towards a forehead pad thatincludes a base portion to contact a user's forehead, a support postcomprising a necked down region connected to the base portion, and ahead adapted to connect the support post to a forehead support of arespiratory mask.

Another aspect of the invention is directed towards a forehead padassembly that includes at least two pads, each pad comprising a baseportion to contact a user's forehead, a support post comprising a neckeddown region connected to the base portion, and a head adapted to connectthe support post to a forehead support of a respiratory mask. Theassembly further comprises at least one connector to connect adjacentbase portions.

Other aspects, features and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles ofpreferred embodiments.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 is a perspective view of a respiratory mask and forehead padaccording to one embodiment of the present invention;

FIG. 2 is a perspective and enlarged view of the forehead support shownin FIG. 1, without the mask frame and pads;

FIG. 3 is a perspective view of one embodiment of a forehead padaccording to the present invention;

FIG. 4 is a perspective view of a respiratory mask and forehead padaccording to one second embodiment of the present invention;

FIG. 5 is a perspective view of another embodiment of a forehead padaccording to the present invention;

FIG. 6 is a top view of a forehead support including a pair of foreheadpads and a forehead of a user;

FIG. 7 is a perspective view of the contact surface of one embodiment ofa forehead pad showing raised surfaces;

FIG. 8 is a cross-sectional view of one embodiment of a forehead padshowing a hollowed out region;

FIG. 9 is a top view of an embodiment of a forehead pad assembly showingtwo pads joined by a flexible connector;

FIG. 10 is a right side view of one embodiment of a forehead pad in arespiratory mask showing contact with a user;

FIG. 11 is a cross-sectional view of one embodiment of a forehead padengaged with one embodiment of a forehead support;

FIG. 12 is a cross-sectional view of another embodiment of a foreheadpad engaged with another embodiment of a forehead support;

FIG. 13 is a cross-sectional view of another embodiment of a foreheadpad engaged with another embodiment of a forehead support;

FIG. 14 is a cross-sectional view of another embodiment of a foreheadpad engaged with another embodiment of a forehead support;

FIG. 15 is a top view of the embodiment of the forehead support shown inFIG. 14;

FIG. 16 is a cross-section of a prior art forehead pad;

FIG. 17 is a cross-section of the forehead pad shown in FIG. 16 in acompressed state;

FIG. 18 is a cross-section of a prior art forehead pad;

FIG. 19 is a front view of a prior art forehead support;

FIG. 20 is a top view of the forehead support shown in FIG. 19;

FIG. 21 is a side view of another embodiment of a forehead pad accordingto the present invention;

FIG. 22 is a bottom view of the embodiment shown in FIG. 21;

FIG. 23 is a top view of the embodiment shown in FIG. 21;

FIG. 24 is another side view of the embodiment shown in FIG. 21;

FIG. 25 is a cross-sectional view of the embodiment shown in FIG. 24along axis 25—25;

FIG. 26 is a perspective view of the embodiment shown in FIG. 21;

FIG. 27 is a perspective view of another embodiment of a foreheadsupport according to the present invention;

FIG. 28 is an end view of another embodiment of a forehead pad accordingto the present invention;

FIG. 29 is a side view of the embodiment shown in FIG. 28;

FIG. 30 is a perspective view of the embodiment shown in FIG. 28;

FIG. 31 is a top view of the embodiment shown in FIG. 28;

FIG. 32 is a rear view of the embodiment shown in FIG. 9;

FIG. 33 is a top view of the embodiment shown in FIG. 32;

FIG. 34 is a front view of the embodiment shown in FIG. 32;

FIG. 35 is an end view of the embodiment shown in FIG. 9;

FIG. 36 is a cross-sectional view of the embodiment shown in FIG. 35along axis 36—36;

FIG. 37 is a an expanded cross-sectional view of the embodiment shown inFIG. 35;

FIG. 38 is a rear view of another embodiment a forehead pad according tothe present invention;

FIG. 39 is a top view of the embodiment shown in FIG. 38;

FIG. 40 is a cross-sectional view of the embodiment shown in FIG. 38along axis 40—40;

FIG. 41 is a front view of the embodiment shown in FIG. 38;

FIG. 42 is an end view of the embodiment shown in FIG. 39;

FIG. 43 is a cross-sectional view of the embodiment shown in FIG. 42along axis 43—43;

FIG. 44 is an expanded cross-sectional view of the embodiment shown inFIG. 42;

FIG. 45 is a cross-sectional view of one embodiment of a forehead padengaged with one embodiment of a forehead support according to thepresent invention;

FIG. 46 is side view of the embodiment shown in FIG. 45;

FIG. 47 is a cross-sectional view of another embodiment of a foreheadpad engaged with another embodiment of a forehead support according tothe present invention;

FIG. 48 is a top view of the embodiment of the forehead pad and theembodiment of the forehead support shown in FIG. 47;

FIG. 49 is a top view of the embodiment of the forehead pad engaged withthe embodiment of the forehead support shown in FIG. 47 during anintermediate assembly step;

FIG. 50 is a front view of a prior art forehead pad;

FIG. 51 is a top view of the forehead pad shown in FIG. 50;

FIG. 52 is bottom side view of the forehead pad shown in FIG. 50;

FIG. 53 is a left view of the forehead pad shown in FIG. 50;

FIG. 54 is a top view of a prior art forehead pad;

FIG. 55 is a perspective view of the forehead pad shown in FIG. 55;

FIG. 56 is a top view of a prior art forehead support;

FIG. 57 is a front view of a prior art forehead support;

FIG. 58 is a top view of another embodiment of a forehead pad accordingto the present invention;

FIG. 59 is a front perspective view of another embodiment of a foreheadpad according to the present invention;

FIG. 60 is a rear perspective view of the forehead pad shown in FIG. 59;

FIG. 61 is a cross-sectional view of the forehead pad shown in FIG. 59along the minor axis;

FIG. 62 is a cross-sectional view of the forehead pad shown in FIG. 59along the major axis;

FIG. 63 is a perspective view of another embodiment of a forehead padaccording to the present invention;

FIG. 64 is a cross-sectional view of another embodiment of a foreheadpad according to the present invention;

FIG. 65 is a cross-sectional view of another embodiment of a foreheadpad according to the present invention;

FIG. 66 is a cross-sectional view of another embodiment of a foreheadpad according to the present invention;

FIG. 67 is a partial cross-sectional view another embodiment of aforehead pad according to the present invention;

FIG. 68 shows an embodiment of a forehead pad according to the presentinvention flexed in a first direction;

FIG. 69 shows an embodiment of a forehead pad according to the presentinvention flexed in a second direction;

FIG. 70 shows an embodiment of a forehead pad according to the presentinvention flexed in a third direction; and

FIG. 71 shows an embodiment of a forehead pad according to the presentinvention flexed in a fourth direction.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

FIG. 1 shows an example of a respiratory mask assembly 100. The maskassembly includes a frame portion 101, a forehead support 102, and aforehead pad 300. The mask is adapted to fasten securely and comfortablyto a user's face. In particular, the mask assembly 100 comprises aseal-forming region 103 that covers the user's nose and/or mouth and acontains opening 104 to which an air delivery tube can be attached. Airor oxygen flows through the opening 104 under positive pressure.

The forehead support 102 is advantageously connected to the frameportion 101 of the mask assembly 100, e.g., by a pivot device 105, whichcan be adjusted to allow the forehead support 102 to the accommodate theconfiguration of a user's face. The forehead support 102 is preferablymade from a thermoplastic material. One embodiment of a forehead supportis shown in greater detail in FIG. 2.

The forehead support 102 can be configured to be essentially straight orit can be curved. The essential straight embodiment is shown in FIG. 2.In the case where the forehead support is curved, the curvaturegenerally follows the curvature of the user's forehead. While this isthe most likely structure, it is within the scope of the presentinvention to use a forehead support 102 that has the opposite curvature,or any combination thereof.

The forehead support 102 can be provided with one or more openings.These openings can be adapted to serve numerous purposes includingpoints of connection to the mask frame, points of connection to anyanother support surface, points of connection 201 for straps to securethe mask to the user, and apertures 202 for a forehead pad.

In a preferred embodiment of the forehead support 102, the apertures 202are designed to receive a head of the forehead pad 300. The apertures202 can be disposed about the forehead support 102 in a manner to allowa user to adjust the position of the forehead pad 300. The apertures 202are also designed to allow a user to attach the forehead pad 300securely to the forehead support 102. In a preferred embodiment, theapertures 202 designed to allow a user to attach the forehead pad 300securely and reversibly to the forehead support 102.

The forehead pad 300 in accordance with a first embodiment of theinvention is shown in greater detail in FIG. 3. The forehead pad 300comprises a base portion 305 to contact a user's forehead, a supportpost 301 connected to the base portion, and a head 302 adapted to beconnected to the forehead support 102. In this embodiment, the head 302is bullet or cone shaped, or otherwise tapered. However, other shapesare possible as long as they serve the purpose of the invention.

The base portion 305, support post 301, and head 302 can be separatepieces, designed to fit with each other. In one embodiment, the baseportion 305 and the support post 301 can be constructed as one piece. Inanother embodiment, the support post 301 and the head 302 can beconstructed as one piece. In yet another embodiment, the base portion305 and the head 302 can be constructed without a support post 301.Finally, in a preferred embodiment, the base portion 305, the supportpost 301, and the head 302 are molded integrally into one piece.

The embodiment shown in FIG. 3 contains a necked down region 303 betweenthe base of the head 302 and the top of the support post 301. In apreferred configuration, the forehead pad is adapted to releasablyengage with the forehead support 102. The function of the necked downregion 303 is to facilitate this feature. The necked down region 303 issuch that its diameter is smaller than the diameter of the base of thehead 302. This results in a lip 304 a between the base of the head 302and the necked down region 303 and another lip 304 b between the neckeddown region 303 and the support post 301.

In a preferred embodiment, the necked down region 303 is at least aslong as the length of the aperture 202 (FIG. 2) in the forehead support102. Insertion of the pad 300 through a first end 200 of the aperture inthe forehead support 102 results in the head 302 passing through theaperture 202 and emerging out a second end 210. The support post 301remains on the side of the first end 200 of the aperture 202 with thenecked down region 303 occupying at least the length of the aperture.This feature results in easy insertion and a tight fit.

Typically, this insertion can be carried out by a user by applying axialpressure to the base portion 305 of the pad 300. While the support post301 is flexible, it can withstand the forces needed for assembly. Usingthe forehead pad embodiment described in FIG. 3 and the forehead supportdescribed in FIG. 2 as examples, the head 302, as well as the lip 304 adistort as axial force is applied against the first end 200 of theaperture 202, until the head and lip 302 and the lip 304 a reach asecond end 210 of the aperture 202, whereupon the lip 310 re-expands toengage a first surface 215 of the forehead support 102 adjacent to theaperture 202. Further, the lip 304 b abuts against a second surface 205of the forehead support 102, to prevent axial movement of the pad 300.

The removal of the pad occurs by applying a pulling force it in adirection opposite to the axial force applied for insertion. Once again,the head 302 and the lip 304 a distort as the lip 304 a disengages withthe first surface 215 of the forehead support 102 adjacent to theaperture 202. Lip 304 a disengages with the second surface 205 of theforehead support 102. Both the head 302 and the lip 304 a regain theiroriginal shape after disengagement from the forehead support 200.

The pressure can be applied by a user's fingers and the successfulinsertion of the pad 300 is indicated not only by the emergence of thehead 302 through the first surface 215 of the aperture 202 but typicallyalso by a clicking sound. The combination of sight, sound, and ease ofinsertion is useful for aged or otherwise infirm users with limitedmanual and/or digital dexterity. The sound produced has the addedbenefit of providing the user of knowledge that the pad 300 has beensuccessfully inserted in the dark. This feature can be of importance dueto the fact that the masks are used at night. Both the forehead support102 and the forehead pad 300 are configured such that the pad 300 can beplaced in different positions on the support 102 so as to achievedifferent positions of contact on the user's forehead.

A wide variety of methods well known to a person skilled in the art forthe manufacture of the base portion, support post, and head. A preferredmethod of manufacture is by injection molding.

The support post 301 can project from the base portion 305 at an angleα, defined between a tangent t to the outer surface of the base portion305 at a point of contact between the support post 301 and the baseportion 305. This angle α can be about 90°, i.e., the support post 301extends essentially straight out from the base portion 305. FIG. 3 showsan embodiment of a forehead pad 300 in which the angle α is about 90°.

FIG. 4 shows another embodiment of a respiratory mask assembly 410. Themask assembly 410 includes of a frame portion 411, a forehead support412, and another embodiment of a forehead pad 400. The forehead support412 is advantageously connected to the frame portion 411 of the mask410, e.g., by a pivot device 413. The mask assembly 410 comprises aseal-forming cushion 414 that covers a user's nose and/or mouth andcontains a swivel elbow 415. The swivel elbow 415 is adapted to receivea supply of air or oxygen flows at positive pressure.

FIG. 5 shows another embodiment of a forehead pad 400 in greater detail.This embodiment of the pad 400 includes a base portion 408, a supportpost 401, and a head 402. The general construction and operation issimilar to that of the first embodiment although there are severaldifferences in the construction, for example, the angle β between thetangent t to the outer surface of the base portion 406 at a point ofcontact between the support post 401 and the base portion 408 is betweenabout 60° and about 120°. Preferably, the angle β is about 70°. Oneadvantage of a support post 401 projecting at an angle less than 90° isto allow the base portion 400 to better fit the contours of a user'sforehead, as shown in FIG. 6.

The support post 401 can be constructed in a manner so as to make itmore flexible. For example, the support post 401 includes cut awayportions 405. These cut away portions help the support post to be ableto be bent or flexed, varying the angle β in use. In this way, a supportpost 401 of larger diameter may be used while still retaining a degreeof flexibility as shown in FIGS. 68 to 71.

The base portion 408 can be of any shape, preferably in a pad-likeconfiguration. In one embodiment, a contact region 407 of the baseportion 408 is shaped so that the transmission of contact forces to thesurface of the forehead of the user takes place under physiologicallycompatible pressures, as shown in FIG. 58. In a preferred embodiment,the contact region 407 is concavely curved to follow the curvature of aforehead.

The contact region 407 can optionally include a raised surface pattern510 as shown in FIG. 7. The pattern 510 reduces the possibility of asuction effect of the pad 400 thereby reducing the drawing of blood inthe region and making the pad 400 more comfortable. The raised pattern510 has the added benefit of reducing sweating. In another embodiment, arear surface of the pad 406 is given a sand-blasted finish to improveventilation and reduce the likelihood of sweating.

The base portion 408 and support post 401 of the pad 400 can alsoinclude a hollowed out region 608 extending a pre-determined distance601 into the base portion 408 and/or the support post 401 as shown inthe cross-sectional view in FIG. 8. In the embodiment shown, thehollowed out region 608 extends through the base portion 408 and partlyinto the support post 401. This structure imparts a degree ofspringiness and flexibility to the forehead pad 400. Due to theessentially incompressible nature of silicone, some cut away regions 405assist flexibility. The use of the hollowed out region 608 allows forsome movement along an axis through the support post 401.

Increasing the diameter of the support post 401 makes the forehead pad400 easier to insert into the forehead support 102. Furthermore, alarger diameter reduces the likelihood of localized pressure points.However, as the support post 401 is made thicker, it becomes lessflexible. Hence the preferred embodiment of the invention balances easeof insertion with flexibility.

In another embodiment, the hollowed out region 608 extends through thebase portion 408, the support post 401, and the head 402 resulting in athrough-bore 509 (shown in FIG. 7). The through-bore 509 may furtherfacilitate compression of the support post 401 and head 402 duringassembly and disassembly. This structure allows a flow of air and/ormoisture to occur from the user's skin to the atmosphere, resulting in areduction of sweating and a more comfortable pad 400.

The support post 401 has a diameter that is in its broadest aspectbetween about 0.1 cm and about 3.0 cm. More specifically the diameter ofthe support post of the embodiment of FIG. 9 is between about 0.5 cm andabout 1.25 cm, and most preferably the diameter is about 1 cm. The term“about” is meant to indicate that the diameters are not absolute and canbe deviated by one skilled in the art. Alternative embodiments, such asthose shown in FIGS. 21 to 31 have different diameters.

The support post 401 has a length that is in its broadest aspect betweenabout 0.1 cm and about 2.5 cm. More specifically the length is betweenabout 0.5 cm and about 1.25 cm, and most preferably the length is about1 cm. Dimensions for one form of forehead pad are shown in FIG. 37. Onceagain, the term “about” is meant to indicate that the lengths are notabsolute and can be deviated by one skilled in the art.

The support post 401 can be straight or it can taper. An example of astraight support post is shown in the embodiment in FIG. 3. The tapercan also be such that the region at the base portion is thicker than thehead region, as shown in the embodiment in FIG. 5.

As would be understood by one skilled in the art, a wide variety ofmaterials can be used to manufacture the forehead pad in accordance withthe present invention. Features of any material used should includebiocompatibility, flexibility and comfort. Some examples of suchmaterials include rubber and flexible plastics. In a preferredembodiment, the pad is constructed from cured Liquid Silicone Rubber(Part# 2666031, Silastic 94-595-HC) manufactured by Dow Coming,alternatively a silicone with a hardness of approximately 35–45 Shore Amay be used. These examples are merely intended to be illustrative andare not limiting in any manner.

In accordance with a preferred embodiment of the present invention, atleast two base pads can be joined in a forehead pad assembly 700. Inthis embodiment, two versions of which are shown in FIGS. 9 and 32 to44, a connector 711 is used to connect adjacent base portions 708. Anytype of connector can be used such as a strap or a flexible bridgeportion. An advantage of a connector is that the assembly 700 has aone-piece design which is less likely to be lost. The plurality of baseportions 708, with contact regions 707, and connectors 711 can beintegrally formed with each other.

As mentioned earlier, the hollowed out region 608 can extend apre-determined distance into the base portion 708 and/or the supportpost 701. This distance can be adjusted to increase flexibility of theforehead pad assembly 700. For example, the hollowed out region 608extends a longer distance into the support post 701 in the embodimentshown in FIG. 44 when compared to the embodiment shown in FIG. 37.Increasing the distance of the hollowed out region 608 has severaladvantages including flexibility, minimization of contact with the edgesof the base portion 708, and better airflow resulting in a reduction insweating by the user.

The hollowed out region 608 can also have a variety of shapes includingconical, pyramidal, cylindrical, or combinations thereof. It is withinthe scope of this invention that the hollowed out region 408 haveadditional sub-structures within it including ridges, bumps, or holes.

In a preferred embodiment, the two base portions 708 of a forehead padassembly 700 are adapted in order to be situated above left and righteyebrows of the user. As shown in FIG. 10, a base portion 708 is shownagainst the user's forehead 813. The support post 701 is designed to actas a spring along the direction of arrow 814. The cut away portions 705improve its flexibility while maintaining ease of insertion. Anotheradvantage of this design is that it can better accommodate rolling andtwisting of the mask 410. A further advantage of the support post 701 isthat its diameter is optimized to reduce the effect of a single point ofpressure on the forehead 813.

The cut away portions 705 define an undercut 720 between the cut awayportions 705 and the base portion 708. The undercut 720 can be a varietyof shapes including curved, square, conical, triangular, or anycombinations thereof. The undercut 720 depth e can also be varied. Thedepth e can range between about 0.25 mm to about 1.25 mm, preferablybetween about 0.5 mm and about 1 mm, and most preferably about 0.75 mm.The term “about” is meant to indicate that the widths and lengths arenot absolute and can be deviated by one skilled in the art.

The number, shape, and size, width w, and length l of the cut awayportions 705 can be varied to serve a variety of purposes including easeof insertion, ease of removal, flexibility of motion when unassembledwith the forehead support, flexibility of motion when assembled with theforehead support, minimization of contact between the user and the edgesof the base portion 708, minimization of contact between the user andthe edges of the forehead support 102, and angles between the foreheadpad assembly 700 and the forehead support 102. The width w can rangebetween about 0.25 mm to about 1.25 mm, preferably between about 0.5 mmand about 1 mm, and most preferably about 0.75 mm. The length l canrange between about 0.05 mm to about 1.5 mm, preferably between about0.25 mm and about 1 mm. Once again, the term “about” is meant toindicate that the widths and lengths are not absolute and can bedeviated by one skilled in the art.

The cut away portions 705 can have regions of similar or differentwidths w and similar or different lengths l. Comparison of theembodiment of the forehead pad assembly 700 shown in FIGS. 32 to 37 withthe embodiment of the forehead pad assembly 700 shown in FIGS. 38 to 44shows a few variations in the cut away portions 705. The width w of thecut away portions 705 in the embodiment shown in FIGS. 38 to 44 is lessthan the width w of the cut away portions 705 in the embodiment shown inFIGS. 32 to 37.

The undercut 720 in FIG. 40 (a cross-sectional view along line 40—40 ofFIG. 39) may be more pronounced than the embodiment of FIGS. 32 to 37.Thus the range of movement of the pad in the vertical plane can beincreased, thereby increasing the range of users the mask will fit. Inaddition, the increased range of movement can help prevent the edge ofthe pad from coming in contact with the user's forehead, therebyincreasing user compliance and comfort. Finally, the increased undercut720, along with the shape and size of the surrounding cut away portions705, can effect the force necessary to flex the base portion 708 withrespect to the support post 701, thereby optimizing the desired flexingforces within levels acceptable to the user while still allowingadequate performance of the forehead pad assembly 700.

One advantage of reducing the width w and/or increasing the depth e isto vary the angle δ between the forehead pad assembly 700 and theforehead support 102, which in turn allows for greater range of motionand user comfort. The angle δ is the angle between a horizontal line hand a line passing through the center of the base portion 708 and thesupport post 701. FIGS. 45 and 46 show the embodiment of the foreheadpad assembly 700 shown in FIGS. 38 to 44 assembled with the foreheadsupport 102. The angle δ is about 25°. The angle δ of the embodiment ofthe forehead pad assembly 700 shown in FIGS. 32 to 37 assembled with theforehead support 102 is about 0°. Once again, the term “about” is meantto indicate that the angles are not absolute and can be deviated by oneskilled in the art.

Presentation of the base portion 708 of the forehead pad assembly 700 atan angle which is generally parallel to the users forehead providesimproved comfort to the user, reducing the likelihood of pressure soreswhich may result from an uneven presentation. In some forms of longmasks, for example a full face mask, the forehead support 102 may bepositioned in use higher up the forehead of the user than in a nasalmask.

In the embodiment of forehead support shown in FIG. 42, the support post701 and base portion 708 are generally perpendicular to one another whenviewed from an end. However, in other embodiments, they may beconstructed at different angles. For a long mask, because of thecurvature of the skull, in order that the base portion 708 of theforehead pad assembly 700 be presented generally parallel to the user'sforehead, either (i) the forehead support 102 should be adapted toretain a perpendicular forehead pad assembly 700 at an angle, as shownin FIG. 45, or (ii) the forehead support 102 should be adapted to retaina non-perpendicular forehead pad assembly 700 at a right angle. In thepreferred embodiment, a perpendicular pad is used and the foreheadsupport 102 is adapted to retain and present the pad to the forehead ofthe user at the appropriate angle. In this way, the same forehead padassembly 700 can be used across a range of mask systems, for example,nasal masks and full face masks, providing an economic benefit to themanufacturer through the use of common parts.

FIG. 11 shows a cross section of an embodiment of a forehead pad 900inserted into an aperture 930 in a forehead support 940. To insert thepad 900, axial force is applied in the direction of arrow 914. The head902 and the lip 904 distort as they pass through the aperture 930. Oncethe head 902 and the lip 904 are through the aperture 930, the neckeddown region 903 of the support post 901 occupies the length of theaperture 930. This results in the lip 905 also making contact with theforehead support 940. The engagement of lips 904 and 905 with respectiveside surfaces of the forehead support 940 results in maintaining the pad900 in position.

To remove the pad 900 from the forehead support 940 the pad 900 ispulled in an opposite direction to arrow 914. Once again, the head 902and/or the lip 904 distort as they pass through the aperture 930 enablethe pad 900 to disengage from the forehead support 940.

FIG. 12 shows a cross section of an embodiment of a forehead pad 408inserted into another embodiment of a forehead support 1040. Theforehead support 1040 has arms 2000 that can move in direction d whenpressure is applied to the pad 408 in direction a. In one embodiment,the movement of arms 2000 results in a plastic deformation, i.e., theremoval of the pad 408 results in the arms 2000 remaining essentially inthe position they were when the pad 408 was inserted. In anotherembodiment, the movement of arms 2000 results in an elastic deformation,i.e., the removal of the pad 408 results in the arms 2000 returningessentially to the position they were before the pad 408 was inserted.The support post 401 can compress in direction b allowing for ease ininsertion and removal but still providing a firm fit. Once inserted, thepad 408 can be adjusted by angle γ.

A cross section of another embodiment of a forehead pad 1000 engagedwith a rigid forehead support 1040 is shown in FIG. 13. The foreheadsupport 1040 comprises lips 1042 and 1043. Lip 1042 of the foreheadsupport 1040 is adapted to engage lip 1004 of the head 1002 and lip 1043of the support post 1040 is adapted to engage lip 1005 of the supportpost 1010. In another embodiment of the invention, the support post 1010is co-molded to the forehead support 1040.

FIGS. 14 and 15 shown another embodiment of a forehead pad 100 engagedwith an embodiment of a forehead support 1040. The forehead support 1040has arms 2001. These arms 2001 define the aperture 1030 and can be movedin direction a to allow for removal of the pad 1000.

In another embodiment of the invention, the support post 1010 includes agenerally cylindrical end region adapted to engage with a key-shapedslot of a forehead support. To attach the stalk to the forehead support,a small-diameter portion of the end region is slid through a generallyrectangular region of smaller diameter, causing it to distort, beforebeing received within a generally cylindrical region having a diameterslightly larger than that of the stalk, as in FIGS. 47 to 49. Thesmaller diameter portion of the end region defines two shoulder regions,similar in function to those of other embodiments, adapted to preventaxial movement of the pad.

In one form, the base portion 408 of the forehead pad is generallyplate- or disc-shaped. In a preferred form, it presents a concavesurface to a forehead of a patient in use. Possible shapes of the baseportion include rectangular and oval shapes.

The shape of the support post 401 and base region 408 is designed tocause lines of force 490 to be smoothly and evenly carried from thesupport post 401 to the base region 408, as shown in FIG. 58. In thisway there is an even distribution of pressure across the user's forehead813. The lines of force 490 are not concentrated. The support post 410is of a design to be sufficiently rigid so that it does not buckle wheninserted and pushed.

An alternative embodiment of a forehead pad according to the presentinvention is shown in FIGS. 59 to 62. In this embodiment, there is a“cleat” on the T-bar arm of the forehead support, the cleat having agenerally oval shape and positioned away from the surface of the arm ofthe forehead support, defining a space between the front side of thecleat and the arm of the forehead support. The pad has a generally ovalshape, defining a major and minor axis and includes a shaft therethroughwith a varying profile. The initial profile is of a complementary shapeto the cleat, allowing the pad to fit on the cleat. Further along theshaft, the profile rotates approximately 90°, defining a shoulderregion. In this way, the pad can be inserted over the cleat and thentwisted approximately 90° to lock it in position. In this position, theshoulder region of the pad engages with the front side of the cleat.

In a preferred embodiment, the pad includes a pair of dimples adapted toengage with corresponding protrusions on the arm of the foreheadsupport. Engagement between the dimples and respective protrusionsprovides feedback to the user that the pad has been correctlyrotationally aligned. Furthermore, the engagement between dimples andprotrusions reduces unintentional rotational movement of the pads.Alternative locking mechanisms, such as those with keys or moveableslider blocks, fall within the scope of the invention.

FIG. 63 shows an alternative embodiment of the invention. In thisembodiment, the arms of the forehead support 102 are generallycylindrical and are covered in a generally cylindrical “pipe” of foam,forming the forehead pad 400. Because of the generally constant radiusof the forehead arm and the pipe, there are no sharp edges presented tothe forehead of the user, regardless of the angle of the support withrespect to the forehead. In one form, the foam only partly surrounds thearm of the forehead support. Furthermore, because of the generallyconstant properties of the foam with respect to angular position, thelines of force are smoothly carried to the forehead of the user. Inanother embodiment, the pipe is shaped so that its outer surfacepositions a thicker section at the forehead and the bore through thepipe need not be circular, permitting attachment to non-circular arms.

In alternative embodiments, shown in FIGS. 64 to 66, the thickness ofthe pipe about a circumference can be varied to provide adjustability.The pipe can have two sections of different thicknesses (FIG. 64), threesections of different thickness (FIG. 65), or can have an eccentricthickness (FIG. 66). These embodiments offer several other advantagesincluding increasing the snugness of the fit without removal of themask, decreasing tightness of the pipe and associated symptoms, e.g.,sweating and discomfort, without removal of the mask.

FIG. 67 shows an alternative embodiment of the invention. In thisembodiment, the tip of the forehead support 102 comprises a generallyspherical ball. A foam or silicone pad 400, also generally sphericallyshaped, is placed over the tip of the forehead support 102. The generalspherical shape smoothly carries lines of force from the tip of theforehead support to the forehead, regardless of orientation. In this waythere is an even distribution of force on the forehead of the user.

While this application has described a few embodiments of forehead padsand forehead supports, it is well understood by one skilled in the artthat various forehead pads, forehead supports, and masks can be usedinterchangeably. A type of forehead pad is not limited to a particularforehead support or to a specific mask.

In an alternative embodiment, the support post of the forehead pad canbe used in combination with an extruded pad such as used on the MIRAGEmask (U.S. Pat. No. 6,119,693). Another embodiment has a forehead paddevoid of a convex surface, instead including a support post used incombination with a concave surface. Another embodiment includes a padwith varying cross-sectional thicknesses, e.g., it could be thinner atedges for greater flexibility when rolling, than at the center.

It can thus be appreciated that the aspects of the present inventionhave been fully and effectively accomplished. The foregoing specificembodiments have been provided to illustrate structural and functionalprinciples of the present invention, and are not intended to belimiting. To the contrary, the present invention is intended toencompass all modifications, alterations and substitutions within thespirit and scope of the present invention.

1. A forehead pad comprising: a) a base portion, wherein the baseportion defines (i) a first surface, (ii) a second surface to contact auser's forehead, wherein the second surface is concave, and (iii) aperimeter including outer and inner sides relative to the user'sforehead in use, and non-parallel upper and lower sides that convergefrom the outer side to the inner side; b) a support post, wherein thesupport post projects from the first surface and comprises a necked downregion; and c) a head adapted to connect the support post to a foreheadsupport of a respiratory mask.
 2. A forehead pad according to claim 1,wherein the support post projects from the base portion and isintegrally molded therewith.
 3. A forehead pad according to claim 1,wherein the base portion and support post include a hollowed out regionextending a pre-determined distance into at least one of the baseportion and support post.
 4. A forehead pad according to claim 1,wherein the support post includes a tapered portion such that a regionat the base portion is thicker than the head.
 5. A forehead padaccording to claim 1, wherein the head includes a tapered portion fromthe support post to a point.
 6. A forehead pad according to claim 1,wherein the diameter of the necked down region is less than the diameterof a base of the head.
 7. A forehead pad according to claim 1, whereinthe support post is axially compressible.
 8. A forehead pad according toclaim 1, wherein the support post has a diameter of between about 0.1 cmto about 1.5 cm.
 9. A forehead pad according to claim 8, wherein thesupport post has a diameter of between about 0.5 cm to about 1.25 cm.10. A forehead pad according to claim 9, wherein the support post has adiameter of approximately 1 cm.
 11. A forehead pad according to claim 1,wherein the support post has a length of between about 0.1 cm to about1.5 cm.
 12. A forehead pad according to claim 11, wherein the supportpost has a length of between about 0.5 cm to about 1.25 cm.
 13. Aforehead pad according to claim 12, wherein the support post has alength of approximately 1 cm.
 14. A forehead pad according to claim 1,wherein the head is adapted to be releasably connected to the foreheadsupport using a push-on motion.
 15. A forehead pad according to claim 1,wherein the support post is sufficiently rigid to distribute lines offorce from the forehead support evenly across the second surface of theforehead pad.
 16. A forehead pad according to claim 1, wherein thesupport post and the base portion are configured to evenly distributeforces across the second surface without localized pressure points. 17.A forehead pad according to claim 1, wherein the forehead pad consistsof the base portion, the support post, and the head.
 18. A forehead padaccording to claim 1, wherein the second surface consists essentially ofthe support post, which is substantially centrally mounted on the secondsurface.
 19. A forehead pad comprising: a) a base portion, wherein thebase portion defines (i) a first surface, and (ii) a second surface tocontact a user's forehead, wherein the second surface is concave, b) asupport post, wherein the support post projects from the first surfaceand comprises a necked down region; and c) a head adapted to connect thesupport post to a forehead support of a respiratory mask, wherein thesupport post projects from the first surface of the base portion at anangle, wherein the angle is defined between a tangent to the firstsurface at a point of contact between the support post and the baseportion, and wherein the angle is between about 60° and about 120°. 20.A forehead pad according to claim 19, wherein the angle is less thanabout 90°.
 21. A forehead pad according to claim 20, wherein the angleis between about 65° and about 80°.
 22. A forehead pad comprising: a) abase portion, wherein the base portion defines (i) a first surface, and(ii) a second surface to contact a user's forehead, wherein the secondsurface is concave, and b) a support post, wherein the support postprojects from the first surface and comprises a necked down region; andc) a head adapted to connect the support post to a forehead support of arespiratory mask, wherein the second surface defines a raised surfacepattern to at least one of: aid in airflow, prevent sweating, andincrease comfort to the user.
 23. A forehead pad comprising: a) a baseportion, wherein the base portion defines (i) a first surface, and (ii)a second surface to contact a user's forehead; b) a support post,wherein the support post projects from the first surface and comprises anecked down region; and c) a head adapted to connect the support post toa forehead support of a respiratory mask, wherein the support postincludes at least one cut away portion and an associated undercutpositioned between the necked down region and the base portion.
 24. Aforehead pad according to claim 23, wherein the at least one cut awayportion has a length of between about 0.05 mm to about 1.5 mm.
 25. Aforehead pad according to claim 24, wherein the at least one cut awayportion has a length of between about 0.25 mm and about 1 mm.
 26. Aforehead pad according to claim 23, wherein the at least one cut awayportion has a width of between about 0.25 mm to about 1.25 mm.
 27. Aforehead pad according to claim 26, wherein the at least one cut awayportion has a width of between about 0.5 mm and about 1 mm.
 28. Aforehead pad according to claim 27, wherein the at least one cut awayportion has a width of between about 0.75 mm.
 29. A forehead padaccording to claim 26, wherein the at least one undercut has a depth ofbetween about 0.5 mm and about 1 mm.
 30. A forehead pad according toclaim 27, wherein the at least one undercut has a depth of between about0.75 mm.
 31. A forehead pad according to claim 23, wherein the at leastone undercut has a depth of between about 0.25 mm to about 1.25 mm. 32.A forehead pad consisting essentially of: a) a base portion having agenerally trapezoidal surface to face a user's forehead; and b) asupport post connected to a central portion of the base portion.
 33. Aforehead pad according to claim 32, wherein the support post issubstantially centrally mounted on the base portion.
 34. A forehead padcomprising: a) a base portion having a generally trapezoidal surface toface a user's forehead; b) a support post connected to the base portion;and c) a head adapted to connect the support post to a forehead supportof a respiratory mask, wherein the support post distributes lines offorce from the head through the support post to the base portion suchthat the lines of force are substantially evenly distributed across thebase portion.
 35. A respiratory mask comprising: a) a forehead supporthaving an aperture and an otherwise entirely smooth surface facing auser in use of the mask; and b) a forehead pad comprising a baseportion, wherein the base portion defines a first surface and a secondgenerally trapezoidal surface opposite the first surface to face auser's forehead; a support post, wherein the support post projects fromthe first surface; and a head adapted to connect the support post to theforehead support.
 36. A forehead pad assembly comprising at least twoforehead pads, each pad comprising: a) a generally trapezoidal baseportion to face a user's forehead; b) a support post connected to thebase portion, wherein the support post comprises a necked down region;and c) a head adapted to connect the support post to a forehead supportof a respiratory mask; wherein the assembly further comprises at leastone connector to connect adjacent base portions.
 37. A forehead padaccording to claim 36, wherein each base portion is adapted to bedisposed above an eyebrow of the user.
 38. A forehead pad according toclaim 36, wherein the connector is flexible.
 39. A forehead padaccording to claim 36, wherein at least two base portion and at leastone connector are integrally formed with each other.
 40. A forehead padaccording to claim 36, wherein at least one base portion and at leastone connector are formed as one piece.
 41. A forehead pad according toclaim 36, wherein the base portion defines a first surface, from whichthe support post projects.
 42. A forehead pad according to claim 41,wherein each base portion defines a second surface that is adapted tocontact the user's forehead, and wherein the second surface is concave.43. A forehead pad according to claim 42, wherein the second surfacedefines a raised surface pattern to at least one of: aid in airflow,prevent sweating, and increase comfort to the user.
 44. A forehead padaccording to claim 36, wherein each base portion and support postinclude a hollowed out region extending a pre-determined distance intoat least one of the base portion and support post.
 45. A forehead padaccording to claim 36, wherein the support post includes a taperedportion such that a region at the base portion is thicker than the head.46. A forehead pad according to claim 36, wherein the head includes atapered portion from the support post to a point.
 47. A forehead padaccording to claim 36, wherein the diameter of the necked down region isless than the diameter of a base of the head.
 48. A forehead padaccording to claim 36, wherein the support post is axially compressible.49. A forehead pad according to claim 48, wherein the support postincludes cut away portions.
 50. A forehead pad assembly comprising atleast two forehead pads, each pad comprising: a) a base portion tocontact a user's forehead; b) a support post connected to the baseportion, wherein the support post comprises a necked down region; and c)a head adapted to connect the support post to a forehead support of arespiratory mask, wherein: the assembly further comprises at least oneconnector to connect adjacent base portions the support post projectsfrom the first surface of the base portion at an angle, the angle isdefined between a tangent to the first surface at a point of contactbetween the support post and the base portion, and the angle is betweenabout 60° and about 120°.
 51. A forehead pad according to claim 50,wherein the angle is less than about 90°.
 52. A forehead pad accordingto claim 51, wherein the angle is between about 65° and about 80°.
 53. Arespiratory mask comprising: a) a forehead support; and b) a foreheadpad comprising: (i) a base portion, wherein the base portion furtherdefines: a first surface, a second surface to contact a user's forehead,wherein the second surface is, and a perimeter including outer and innersides relative to the user's forehead in use, and non-parallel upper andlower sides that converge from the outer side to the inner side, (ii) asupport post, wherein the support post projects from the first surfaceand comprises a necked down region; and (iii) a head adapted to connectthe support post to a forehead support.
 54. A respiratory mask accordingto claim 53, wherein the forehead support is essentially straight.
 55. Arespiratory mask according to claim 53, wherein the forehead support iscurved.
 56. A respiratory mask according to claim 53, wherein theforehead pad connected to the forehead support does not project a hardsurface to the user' forehead.
 57. A respiratory mask according to claim53, wherein the forehead pad is secured to the forehead support by onlythe support post.
 58. A respiratory mask according to claim 53, whereinthe support post is axially compressible.
 59. A respiratory maskaccording to claim 58, wherein the support post includes cut awayportions.
 60. A respiratory mask according to claim 53, wherein theforehead support includes at least one aperture.
 61. A respiratory maskaccording to claim 60, wherein the forehead support comprisescompressible regions in proximity with the aperture.
 62. A respiratorymask according to claim 60, wherein the head includes a tapered portionfrom the support post to a point in order to releasably insert the headin the aperture.
 63. A respiratory mask according to claim 60, whereinthe diameter of the necked down region is less than the diameter of abase of the head, such that the head can be releasably inserted into theaperture in order to securely attach the forehead pad to the foreheadsupport.
 64. A respiratory mask comprising: a) a forehead support; andb) a forehead pad comprising: (i) a base portion, wherein the baseportion further defines: a first surface, a generally trapezoidal secondsurface to face a user's forehead; (ii) a support post, wherein thesupport post projects from the first surface and is adapted to connectto the forehead support, wherein the base portion is connected to theforehead support solely through the support post.
 65. A respiratory maskaccording to claim 64, wherein a surface of the forehead support thatfaces the forehead pad includes no protrusions.
 66. A forehead padcomprising: a) a base portion, wherein the base portion further defines:(i) a first surface, and (ii) a generally trapezoidal second surface toface a user's forehead; b) a support post, wherein the support postprojects from the first surface and is adapted to connect to theforehead support, wherein the second surface substantially evenlydistributes force across the forehead pad without localized pressurepoints.